Method for manufacturing wood fiber insulating boards

Abstract

The invention relates to a method for manufacturing wood fiber insulating boards, wherein wood fibers are mixed with thermoplastic plastic fibers as binders and a fiber mat is produced therefrom, wherein multi-component fibers composed of at least one first and one second plastic component having different melting points are used as plastic fibers, wherein the fiber mat is heated in such a way that the second component of the plastic fiber softens and wherein the fiber mat is cooled down to produce the insulating board, characterized in that a steam / air mixture having a specified dew point flows through the fiber mat to heat the fiber mat and that multi-component plastic fibers are used as binders, the first component of which has a melting point above the dew point and the second component of which has a melting point below the dew point.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is the US national stage of PCT application PCT / EP2009 / 005912, filed 14 Aug. 2009, published 4 Mar. 2010 as 2010 / 022864, and claiming the priority of German patent application 102008039720.2 itself filed 26 Aug. 2008.FIELD OF THE INVENTION[0002]The invention relates to a method of making wood-fiber insulating boards where wood fibers are mixed with thermoplastic plastic fibers as binders and a fiber mat is produced therefrom, and where multicomponent fibers composed of at least one first and one second plastic component having different melting points are used as plastic fibers, and where the fiber mat is heated in such a way that the second component of the plastic fiber softens, and where the fiber mat is cooled to produce the insulating board.BACKGROUND OF THE INVENTION[0003]The production of boards of wooden raw material using wood fibers on the on hand and bicomponent plastic fibers on the other hand is known in the ...

AI Technical Summary

Benefits of technology

[0007]The object of the invention is to provide a method for the easy and cost-effective production of flexible wood-fiber insulating boards of high quality and at an affordable price.SUMMARY OF THE INVENTION

[0009]First and foremost, the invention relies on the (known) discovery that flexible insulating boards usable, for example, as heat- and / or cold- and / or as sound-insulating boards can be produced by using multicomponent plastic fibers, for example two-component plastic fibers, as a binder. When heated, the one component partially melts or softens (for example, the outer component), while the other component (for example, the inner component) remains substantially dimensionally stable, thereby achieving, on the one hand, an internal interconnection within the board and, on the other hand, high elasticity and / or flexibility of the board due to the embedded plastic fibers as well. The plastic fibers thus have a double function in that, on the one hand, as a binder they provide the interconnection and, on the other hand, they ensure the elasticity and / or flexibility of the board. But the invention provides for the heating, and therefore the partial melting of the second component, not by way of hot air but by way of steam or a steam-air mixture that flows through the fiber mat having a dew point TP=100° C. This results in especially fast, and therefore cost-effective, heating of the fibers because the steam condenses at a defined dew point on the cold wood and plastic fibers, thereby transferring the necessary heat for the partial melting of the second plastic component, for example the jacket of the bicomponent fibers. In contrast to conventional hot-air heating, with this condensation it is possible to achieve very quick heat input. This allows, in turn, for short heat treatment periods and therefore a continual process and a short construction length of the required heating device. This process in the manufacture of the described insulating boards is made possible by multicomponent plastic fibers that are used as binder and whose first component has a melting point T1 above the dew point of the steam-air mixture and whose second component has a melting point T2 below the dew point of the steam-air mixture. Consequently, in particular for the second component, a plastic having a comparatively low melting point or softening point of below 100° C., preferably less than 95° C. is used.

[0010]To this effect, it is possible to use multicomponent plastic fibers, for example bicomponent fibers, having a core-jacket structure where the first component constitutes the core and the second component the jacket. Alternatively or additionally, it is also possible to use multicomponent plastic fibers, for example bicomponent fibers, having a side-by-side structure.

[0016]The boards that are manufactured within the scope of the present invention are of high quality and sufficiently flexible to be suitable for use as between-rafter insulation.

Problems solved by technology

But such developments did not influence the manufacture of wood-fiber insulating boards with multicomponent plastic fibers.

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